|
%I #12 Feb 09 2018 04:51:08
%S 100,105,108,110,120,121,130,132,135,140,143,150,154,160,165,170,176,
%T 180,187,190,192,195,198,200,220,225,231,240,242,253,260,264,275,280,
%U 286,297,300,315,330,341,352,360,363,374,385,390,396,400,405,440,451
%N Gapful numbers >= 100: numbers that are divisible by the number formed by their first and last digit. Numbers up to 100 trivially have this property and are excluded.
%H Aaron Toponce, <a href="/A108343/b108343.txt">Table of n, a(n) for n = 1..10000</a>
%e 253 is in the sequence because 253 = 11 * 23 and 23 is the concatenation of 2 and 3 (first and last digit of 253).
%t fQ[ n_ ] := Block[ {id = IntegerDigits[ n ]}, IntegerQ[ n / FromDigits[ {id[ [ 1 ] ], id[ [ -1 ] ]} ] ] ]; Select[ Range[ 100, 461 ], fQ[ # ] & ] (* _Robert G. Wilson v_, Jul 19 2005 *)
%K nonn,base
%O 1,1
%A _Luca Colucci_, Jul 01 2005
%E Corrected and extended by _Robert G. Wilson v_, Jul 19 2005
|
